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[AMPS] Cathode Impedance Measurements

To: <amps@contesting.com>
Subject: [AMPS] Cathode Impedance Measurements
From: jono@enteract.com (Jon Ogden)
Date: Mon, 29 Mar 99 10:31:40 -0600
>Hi Jon & all..
>
>Jon, no doubt you've got good, useful info. But, with all due respect, I 
>think you're a little off the deep end dissing "the so-called experts who 
>said it wouldn't work" without explaining why it DOES work. (My apologies 
>to all if someone has already made this point & I missed it!)

Well, I thought I covered it when the subject was first brought up a 
couple of months ago.
>
>We know that a gg tube in class AB2 or B does in fact "look" pretty much 
>like its input C, in parallel FOR LITTLE MORE THAN HALF THE RF CYCLE with a 
>resistive load.

Undoubtably I agree.


>
>So WHY does it work to adjust matching with more or less pure resistance 
>simulating the "half-cycle resistor" dynamic load actually presented by the 
>tube? It's because the value of "Rin" that you tack across the tube is 
>really an AVERAGE value of Rin.

Correct.  You stated it very well.  It's the average value that the 
exciter sees over the cycle.  And yes, without the flywheel effect of the 
tuned input circuit, you would experience different numbers.  

You stated it better than I could have anyhow! :-)

73,

Jon
KE9NA


--------------------------------------------------------------------------
Jon Ogden

jono@enteract.com
www.qsl.net/ke9na

"A life lived in fear is a life half lived."


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